Separator arrangement for gas/liquid separation; apparatus; and, methods

ABSTRACT

A serviceable gas/liquid separator is provided. The gas/liquid separator has a cross-section with one long axis and one short axis, with an aspect ratio of at least 1.3. A preferred cross-section, is an elliptical cross-section. Assemblies in which the separator unit can be used, are provided. In addition methods of use and construction are provided.

The present application includes the disclosure of (with edits) U.S.Provisional Application 60/520,906 filed Nov. 17, 2003. Priority to the60/520,906 filing is claimed to the extent appropriate. The completedisclosure of U.S. application 60/520,906, is incorporated herein byreference.

FIELD OF THE INVENTION

The present disclosure relates to gas/liquid separation. The disclosureparticularly concerns serviceable separator arrangements for use inconducting gas/liquid separation. It also concerns apparatus or systemsin which such separators are used, methods of operation and separation,and methods of assembly. A particular, useful, application is as anair/oil separator for air compressors.

BACKGROUND

A variety of equipment types and systems utilize gas/liquid separationassemblies. Examples include: compressors and compressed air systems;and, industrial mist collectors.

In general, such assemblies include a removable and replaceable (i.e.,serviceable) separator unit, construction or arrangement. In someassemblies a single serviceable separator element is used as theseparator element construction; and in others, multiple serviceableelements are used. In general, operation involves directing a gas/liquidflow through the separator unit, i.e., through the serviceable separatorelement or elements. Within the separator unit, liquid coalescing anddrainage occurs. As a result, an entrained liquid concentration, withinthe gas stream, is reduced. Periodically, the serviceable element(s) areremoved and replaced.

SUMMARY

Herein, techniques applicable for using gas/liquid separation assembliesare provided. The techniques include provision of unique gas/liquidseparator elements, with respect to outer and/or inner shapes.

Other techniques provided herein include preferred orientation ofgas/liquid separator element(s) within separator arrangement; preferredinternal constructions for separator arrangements; and, preferredelement definition. Methods of assembly and use are also provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of an air/oil separator assemblyincluding two serviceable separator elements, according to the presentdisclosure.

FIG. 2 is a cross-sectional view of the assembly depicted in FIG. 1,taken from an orientation at right angles to the view of FIG. 1.

FIG. 3 is a top plan view of the assembly of FIG. 1, shown with the topcover removed.

FIG. 4 is a cross-sectional view taken along line 4-4, FIG. 1.

FIG. 5 is a cross-sectional view taken along line 5-5, FIG. 2.

FIG. 6 is top plan view of a serviceable separator element usable in theassembly of FIGS. 1-5.

FIG. 7 is a cross-sectional view taken along line 7-7, FIG. 6.

FIG. 8 is a cross-sectional view taken along line 8-8, FIG. 6.

FIG. 9 is a schematic cross-sectional view of a gas/liquid separatorassembly having a single serviceable separator element therein.

FIG. 10 is a top view of the assembly depicted in FIG. 9, with the topcover removed.

FIG. 11 is a schematic top view of a gas/liquid separator assemblyhaving three serviceable separator elements therein, depicted with thetop cover removed.

FIG. 12 is a perspective view of a second embodiment of a serviceableseparator element, useable in the assembly of FIG. 1.

FIG. 13 is a top plan view of the separator element of FIG. 12.

FIG. 14 is a cross-sectional view taken along line 14-14, FIG. 13.

FIG. 15 is a cross-sectional view taken along line 15-15, FIG. 13.

DETAILED DESCRIPTION I. General Background

In general, a component of typical gas/liquid separator arrangements ofthe type of concern herein, is the removable and replaceable, i.e.,serviceable, separator arrangement. The removal and replaceable, (i.e.,serviceable) separator arrangement generally comprises one or moreseparators (or separator elements) that, in time (due to operation ofthe gas/liquid separation assembly) are removed and replaced duringservicing operation; hence the term “serviceable.” Typically, eachserviceable separator element includes a media pack, through which thegases are passed. Each media pack typically includes layers or stages ofmedia for conduct of coalescing and drain steps.

Herein, gas/liquid separator assemblies or separator elements will becharacterized or classified as either “in-to-out flow” or “out-to-inflow,” depending on whether, in use, during gas flow through the mediapack of each separator element, gas flow is directed from outside of theserviceable separator element(s) to an interior; or, from an interior ofthe serviceable separator element(s) to an exterior. The techniquesdescribed herein can be applied to either or both. The examples depictedin the drawings relate to in-to-out flow arrangements.

The principles described herein, with respect to gas/liquid separation,can be applied in many arrangements, with one type of typicalapplication being as a gas/oil (specifically air/oil) separator for acompressor arrangement. Such an apparatus is generally adapted foroperation with internal pressures on the order of about 60 psi to 200psi (about 4.2-14.06 kilograms/square cm), for example about 80-120 psi(about 5.6-8.44 kilograms/square cm), typically about 100 psi (about 7kilograms/square cm). Examples of use would be with compressors about 28hp to 500 hp (about 14.9-373 Kw).

The through put for an air/oil separator for use in the compressorarrangement, is typically measured in terms of volume of free air (benon-compressed volume) passed through the separator assembly. A typicaloperating flow would be from on the order of 100 cubic feet per minute(47,000 cubic cm/second) up to several thousand cubic feet per minute(about 1 million cubic cm/second or more).

Herein some particular arrangements for air/oil separation in compressorsystems are shown. The techniques and principles described herein can beapplied in a variety of systems of a variety of sizes, for use with awide variety of equipment types and sizes (for example a variety ofcompressors).

In some instances, the techniques described herein can be applied inother applications, for example in mist collection arrangements such asindustrial mist collectors, or in air/water separators in compressed gassystems. Issues of application, merely relate to adaptation of thevarious techniques described herein, to such assemblies.

II. The Assembly of FIGS. 1-5

In FIGS. 1-5, a gas/liquid separator usable as an air/oil separator thatincludes a preferred separator element arrangement according to thepresent disclosure is depicted. The reference number 1, FIG. 1,generally designates a gas/liquid separator assembly according to oneembodiment of the present disclosure. In general, the assembly 1comprises: a vessel 4, in this instance a pressure vessel 5 including ahousing 6 and top cover 7; and, an internally received, removable andreplaceable or serviceable, separator unit 9, in this instancecomprising two, serviceable, separator elements or separators 10. Theparticular separators 10 depicted are in-to-out flow separators 11, aswill become apparent. An o-ring seal between the cover 7 and housing 6is shown at 8. The cover 7 is secured in place by bolts 7 a. Typicallythe bolts 7 a would be positioned in a ring, on cover 7; and, typicallysix to twelve such bolts would be used.

In general, the pressure vessel 5 includes: a gas flow inlet 12; a gasflow outlet 13 (not viewable in FIG. 1, see FIG. 2); and, a liquid drainoutlet 16. In operation, a gas stream having liquid therein, is directedinto interior 18 of the assembly 1, through inlet 12. Within theassembly 1, the gas stream is eventually directed through media packs20, of the separators 10, and is then passed outwardly from the pressurevessel 5, in this instance through gas flow outlet 13 (FIG. 2). Theparticular arrangement shown in FIG. 1, uses in-to-out flow separators11. By this, it is meant that when the gases pass through the mediapacks 20 of the separators 10, they pass from the interior 10 a ofseparators 10 (defined and surrounded by media packs 20) to an exteriorregion 21 as indicated generally by arrows 22.

Still referring to FIG. 1, for the assembly 1 depicted: the inlet 12 isa sidewall inlet 12 a, meaning it extends through sidewall 5 a; and,drain 16 is a bottom drain. By “bottom” in this context, reference ismeant to a lower portion 23 of assembly 1 when oriented for typical use,as shown in FIG. 1. The term “sidewall” is meant to refer to the housingwall portion 5 a which extends between cover 7 and the bottom 23.

To facilitate operation, the assembly 1 generally defines an enclosedupper region 25 and an enclosed lower region 26, in this instanceseparated by divider or tube sheet structure 28. The tube sheetstructure 28 is generally solid and non-porous to gas flow therethrough, except in specified regions as defined. In this instance thetube sheet structure 28 defines two central apertures 33 therein. Butfor apertures 33, the tube sheet structure 28 is generally solid andpreferably includes: an annular mounting flange 35; a depending centralwall 36, in this instance having an upper funnel section 36 a and alower generally cylindrical section 36 b; base 37, with central aperture33 therein; and lower shroud 38. The base 37 is attached at lower edge36 c of wall 36. The lower shroud 38 depends from the base 37. The wall36 and base 37 generally define an upper sump 39, discussed below. Aswill be understood from detailed description below, apertures 33 provideflow channels for gas flow from lower region 26 into upper region 25,specifically by flow direction into the separator unit 9; i.e. into theindividual in-to-out flow separators 11.

The central wall 36 is preferably a radially continuous wall. By theterm “radially continuous” in this context, it is meant that it extendscontinuously around a central axis 47. There is no specific requirementthat the wall 36 have the funnel shaped portion 36 a indicated. Such aconfiguration, however, is convenient for preferred sump definition andthrough put.

Lower region 26, of the vessel 5, includes lower sump region 40 in thisinstance depicted with liquid (oil) 41 therein. Much of the liquidinitially included within the inlet gas flow, from gas flow inlet 12drains to lower sump region 40, before the gases even pass throughaperture 33 into upper region 25.

Assembly 1 includes, in region 26, a lower sump filler pipe 44 (FIG. 1).The filler pipe 44 provides for an optional entry of liquid into lowersump 40 to facilitate operation, if desired, for example when theassembly 1 is first put on line. A sight glass 45 (FIG. 2) is provided,to observe liquid level. Oil return 46 (FIG. 2) can be used to providefor circulation. The arrangement 1 can also be provided with a reliefvalve tap 43, FIG. 3, if desired. Also temperature taps, not shown, canbe provided. The particular size, number and location of taps andapertures is a matter of choice, for the particular operation intended.A preferred radial location (around central axis 47) of relief valve tap43 relative to inlet 12 is shown in FIG. 3.

Referring to FIG. 1, in sump 40, an operating liquid (oil) level 41 a isshown. In typical use, the amount of oil contained within sump 40 is amatter of choosing an appropriate oil volume that will lead to a desiredaverage temperature or cooled temperature, appropriate for directing oilback to the mechanical system for the compressor of concern. Atemperature probe, not shown, can be used to monitor this.

As indicated, separators 10 are removable and replaceable, i.e.,serviceable, components. The separators 10 each comprise a media pack 20(in this instance each has an elliptical media pack 20 a, incross-section) secured at one end 49 to an end cap 50. For theparticular assembly shown in FIG. 1, each end cap 50 is a closed end cap50 a, meaning that it has no air flow aperture therethrough whichcommunicates with interior 10 a of the associated one of separators 10.

Each separator 10, at an end 55 opposite the end cap 50, includes an endcap 56 with central aperture 57 therein. The central aperture 57 is agas flow aperture, for passage of gases into the interior 10 a of theassociated separator 10 during use. In general, each aperture 57 isaligned with one of the apertures 33, such that gas flow passing throughaperture 33 from region 26 into region 25, is directed through apertures57 into interior 10 a of separator 10.

A variety of seal arrangements could be used at the juncture betweeneach separator 10 and the tube sheet construction 28. For example,either a radial seal or an axial seal or both can be used. In theexample shown in FIG. 1, a radial seal structure 58 is used.

For the example shown, each aperture 33 in the tube sheet arrangement28, is surrounded by an axial wall section in the tube sheet structure28. Each end cap 56, FIG. 1, includes an axially directed projection orspigot 60 thereon, projecting away from the associated media pack 20.Each radial seal structure 58 comprises an o-ring 58 a mounted on anoutside of the spigot 60. The sealing occurs when the spigot 60 ispushed into an associated receiver in the tube sheet structure 28.

Of course in the alternative, a radial seal could be formed with acylindrical projection on the tube sheet structure 28, projecting intoan opening in each open end cap.

The term “radial” when used herein reference to a seal, is meant torefer to a seal positioned for sealing pressure directed radially towardor away from central axis 47. The term “axial” when used in connectionwith a seal, is meant to refer to a seal with a sealing force directedin the general direction of the longitudinal extension of the systemlongitudinal axis 47. For example the o-ring 8 provides for an axialseal.

In general, if the separators 10 were provided with axial seals, a sealring could be provided projecting axially outwardly from each end cap56. This seal would be positioned to engage a portion of base 37, duringsealing. An arrangement to provide pressure would be needed, to ensurethe seal. This pressure could be provided by the cover 7, or byalternate constructions. (Of course alternate axial seals could involvegaskets separate from the elements.)

Referring to FIG. 1, it is noted that in some instances the axial lengthof separators 10 may be slightly shorter than the distance between cover7 and base 37. In use, the separators 10 would be installed asdescribed, by hand, through an opening with cover 7 removed. Cover 7would then be installed (bolted) in place. Under operating pressures,the separators 10 would typically be biased until they bump againstcover 7. The radial seal arrangement would be configured to allow forthis movement, without loss of seal. Construction in this mannerfacilitates manufacture of the separators 10, since tight manufacturingtolerances for length would not be critical.

Attention is now directed to FIG. 3. In FIG. 3, the assembly 1 isdepicted with a top cover 7 (FIG. 1) removed. One can see an uppersurface piece 61. The upper surface piece 61 includes a somewhathourglass shape aperture therein 62, shaped to define around the outsideof the separator elements 11, with projections 63 extending partiallybetween the elements. The hourglass shaped opening 62 helps ensure thatthe two elements 11 are appropriately radially oriented, when placedinto the housing 5.

Still referring to FIG. 3, the bolt holes are indicated generally at 64;and, a receiver groove for the o-ring is at 65.

Referring to FIG. 1, the particular pressure vessel 5 depicted, has acylindrical outer wall 71 and a rounded bottom 72. The cylindrical outerwall 71 defines central axis 47, which generally passes through a center75 of the rounded bottom 72.

In general, gas/liquid separators of the type of concern here areprovided with one of two types of gas inlet arrangements. A first,generally referred to herein as a tangential gas inlet, is a gas inletwhich has a center line directed generally tangentially with respect tothe rounded or cylindrical outer wall 71. The drawings of thisdisclosure do not show a tangential inlet, but a conventional one couldbe used with many of the disclosed principles. In general, housingshaving tangential inlets are relatively expensive to manufacture, bycomparison to the second type of gas inlet discussed below. Thus, it maybe preferred to avoid tangential inlets, for cost reasons.

The second type of gas inlet, shown in FIG. 4, is generally referred toherein as a “radial” or “radially directed” inlet. The particular inlet12 depicted in FIG. 4 is a radially directed inlet 77. In general, aradially directed inlet 77 is an inlet directed with a gas flowgenerally toward the central longitudinal axis 47 of the pressure vessel5. For the particular example shown, center line 78 of gas inlet 77 isdirected to intersect longitudinal axis 47, although this is notspecifically required.

It is noted that the outlet 13, FIG. 2, is a radial or radially directedoutlet 13 a, using the same definition, except for outlet flow insteadof inlet flow.

It should be apparent why radial inlets (and outlets) are less expensivethan tangential inlets (and outlets), to construct. In particular, aradial inlet is typically merely an aperture provided in the sidewall71, with a feed tube or similar structure secured thereto.

Referring to FIG. 1, the assembly 1 includes a preseparation arrangement80. In general, the preseparation arrangement 80 provides for someinitial separation of gas and liquid, upon gas/liquid flow enteringinterior 18, through entrance or inlet 12. For the particulararrangement depicted, the preseparation arrangement 80 includes an inletbaffle arrangement 82.

The preseparation arrangement 80 may be configured generally in accordwith, and under the principles of, the disclosure of U.S. provisionalapplication 60/431,432 filed Dec. 6, 2002, the complete disclosure ofwhich is incorporated herein by reference. Modifications in specificconfiguration to fit the application can readily be made.

In general terms, the inlet baffle arrangement 82 of the preseparationarrangement 80 is configured and positioned so that when liquid andgases enter inlet 12, they are moved through an arcuate path which:tends to drive a portion of the liquid into baffle or wall structure,for collection and drainage out of the gas flow; and, which directs thegases (gas/liquid mixture) into a preferred flow path, to facilitateseparation. In general, a function of such an arrangement is to obtainsubstantial gas/liquid separation, before the gases are passed intoserviceable separator unit 9, without undesirable levels of restriction.

Many air/oil separators utilized with compressors are used incircumstances in which the inlet flow includes not only oil particlesentrained in gases, but also a large amount of bulk liquid oil flow.Such an oil flow into the separator assembly 1, for example, can be onthe order of 8 to 100 gallons per minute (about 30-380 liters/minute).Thus, in many instances, the assembly 1 must be configured to manage alarge amount of bulk oil flow, along with the gas flow and gas/liquidseparation.

The particular inlet baffle arrangement 82 depicted, FIG. 2, includesaxial shroud section 85; and, inlet skirt 86. The axial shroud 85preferably comprises an outer surface to wall 28. Preferably the axialshroud 85 is generally cylindrical, and most preferably it is radiallycontinuous.

The inlet skirt 86 is generally ring-shaped and extends radiallyoutwardly (relative to axis 47) in extension between a point 85 aadjacent the axial shroud 85 and interior surface 87 of housing wall 71.As will be apparent from the following, the particular preferred inletskirt 86 depicted, FIG. 4, is not radially continuous. The inlet skirt86 defines a downcomer or channel arrangement 92 (not shown in FIG. 1,see FIG. 4). In this instance the downcomer or channel 92 provides aportion 93 in inlet skirt 86 opening a space between the shroud 85 andsidewall 71. A variety of alternative downcomers could be used, the oneshown involving a single space 93, being a convenient example.

Referring to FIG. 2, preferably inlet skirt 86 includes an upper surface86 a configured as a radial drainage declination surface, to causedrainage of liquid collected thereon, by gravity, toward a radiallyouter edge 86 b of the skirt 86. In this way, liquid collected onsurface 86 a will tend to drain toward inner surface 87 of wall 71, FIG.2. This will include the bulk oil flow.

Referring again to FIG. 1, as a gas/liquid combination enters pressurevessel 5 through entrance 12, the initial inlet flow is directed intopreseparation arrangement 82. In the preseparation arrangement 82, thegas flow is initially directed toward axial shroud 85 and radial skirt86. A portion of liquid contained within the gas stream, will tend tocollect on the shroud 85 and radial skirt upper surface 86 a. Due to thedownward and outer taper or slant (decline) of the skirt 86, inextension from the shroud 85 to wall 87, the collected liquid will tendto flow under gravity, toward the outer wall 87. Eventually, the liquidwill drain from the region 98, FIG. 2 (defined above skirt upper surface86 a) down into lower sump 80, by passage through downcomer or channel92, FIG. 4. In general, bulk liquid flow toward downcomer 92 will befacilitated by the gas flow.

Referring to FIG. 4, in general, edge 86 c of skirt 86 is positioned atthe same axial height as is edge 86 d. This will be a particularlyconvenient construction to manufacture. Edge 86 c could alternatively bepositioned slightly lower than edge 86 d, to facilitate liquid drainagealong surface 86 a, toward gap 92; and, to facilitate gas flowmaintaining a spiral flow in region 26, after passage through gap 92.

Because the inlet 12 is a radial inlet 12 a, initial flow of agas/liquid combination into the pressure vessel 5, directed towardcentral axis 47, is not automatically directed into a spiral flowpattern. To facilitate flow direction into a spiral pattern, thepreseparation arrangement 82 includes a radial flange or vane 100therein, FIG. 4. The flange or vane 100 extends upwardly from surface 86a in a direction opposite to the direction of declination of skirt 86and will operate to close one direction of possible flow for inletgases, during operation. For the particular arrangement shown in FIG. 4,the flange 100 is positioned to prevent a clockwise flow, (i.e.,clockwise when viewed from the viewpoint of FIG. 4), in the direction ofarrow 105. (Of course the equipment could be configured for an oppositedirection of flow.) It is expected that the flange 100 will typically belocated a radial spacing or distance of no more than 45°, typically nomore than 30° from the closest edge of inlet 12. Indeed, vane 100 ispreferably located as close to the inlet 12 as possible. Preferably vane100 is positioned spaced radially, clockwise in the view of FIG. 4,i.e., over surface 86 a, at least 200° from the edge 53 a of gap 93,typically at least 230°, more preferably at least 250°.

Referring to FIG. 2, for the axial shroud 85 and skirt 86 creates anannular flow region 111 (FIG. 2) between the shroud 85 and wall innersurface 87.

Relief valve tap 43 (FIG. 4) extends through wall 71 into communicationwith flow region 111. Typically and preferably, the relief valve tap 43is located adjacent vane 100, on an opposite side thereof from inlet 12.

It is foreseen that in some instances it would be preferred to providean overall cross-sectional area for region 111, i.e., a cross-sectionalarea for the volume defined by the outer wall 71, shroud 85 and baffle86, which has about the same area as the cross-sectional area or inletarea of inlet 12. In this manner, the flow velocity around annulus 111will not increase substantially relative to the flow velocity throughinlet 12. Avoidance of a large increase in flow velocity in this regionwill generally be preferred, since it will help avoid entrainment (intothe gas flow) of separated liquid.

In addition, a large flow velocity reduction in region 111 willpreferably be avoided to reduce loss of centrifugal force used forseparation of some liquid droplets by driving them against wall 71,while the gases flow around shroud 85.

For a typical preferred arrangement, FIG. 2, the upper surface 86 a ofradial skirt 86 will extend in radial extension from waist or interioredge or region 113 to outer edge or exterior region 114 at a declinationangle A, FIG. 2, the order of at least about 20°, typically at an anglewithin the range of 30° to 80° inclusive (for example 40°-70°). The term“decline” and variants thereof in this instance refers to a downwardangle when the arrangement is oriented for normal use with drain 16directed downward. In general, the choice of declination angle A will inpart be a function of ensuring that the appropriate cross-sectional area111 is provided. In addition, it will be chosen to facilitate a rate offlow of the bulk liquid or toward wall 71.

Referring to FIG. 2, preferably shroud 38 depends adequately, belowskirt 86, such that gasses passing through gap 92, FIG. 4, must passdownwardly and around lower edge 38 a, before passing upwardly into theserviceable separator arrangement 9. This helps avoid undesirable levelsof entrainment in the gasses, as they are passed into the separatorarrangement 9. The shroud 38 and skirt 86 can be parts of a single,integral, piece, as shown. Alternatively, they can be separately mountedcomponents. Unlike skirt 86, preferably shroud 38 is radiallycontinuous.

In the embodiment shown, the downcomer channel 92, FIG. 4, is a gapprovided in skirt 86 which extends completely between shroud 85 and wall71 (FIG. 1). An advantage to this is that as both liquid and gases flowdownwardly through the downcomer or channel 92, the gases do not expandunderneath the skirt 86, toward the shroud 85 or the wall 71, with arisk of re-entrainment of liquid. Typically and preferably, a radialwidth of the downcomer channel 92 will be at least 90% of the distanceof extension of the skirt 86, between inner waist or edge 113 and outeredge 114 (or 86 b). Preferably it will be at least 95% of the distance,most preferably 100% of the distance, as shown.

The downcomer or channel 92, FIG. 4, is generally located to begin atedge 93 a spaced (in the direction of gas flow) at a radial positionrelative to center line 78 of the inlet 12, at an angle of at least 70°,typically at least 180°, often at least 230°, for the example shownabout 250° to 340° around the shroud 85. Also, preferably gap ordowncomer channel 92 is radially spaced at least 200° from vane 100,more preferably at least 230°, typically at least 250°, in the directionof gas flow. This will provide an increased amount of liquid separation,before gas flow can leave preseparation arrangement 80. The radiallength of the skirt 86 and the downcomer channel 92 are generally amatter of choice, based upon desired flow rates and restrictions for thedowncomer channel, usually a radial extension of at least about 30°, andnot more than 130°, and typically 30°-80°, inclusive, for example about40° to 60°, will be used. The term “inclusive” when used herein inreference to a range, is meant to indicate that the end points areincluded in the stated range. All stated ranges are intended to be“inclusive” even if the term is not specifically used.

Referring to FIG. 2, above separator sheet 28, and around separatorelement arrangement 9, is positioned sump 39. A suction tube 115 isshown, extending through tap 116, for draw of collected liquid materialfrom this region.

III. Serviceable Separator Elements

A unique and advantageous construction for the serviceable separatorelements 10, is depicted in FIGS. 6-8.

A characteristic of the preferred separator elements 10 shown, is thatthey have perimeter shapes that are not circular in cross-section (takeorthogonal to a central longitudinal axis), but rather are defined withthe media pack having one long and one short cross-sectional centralaxis. One useable perimeter shape for the media pack is a generallyobround or oval cross-section, a specific example of which is anelliptical cross-section. Examples of other possible shapes includeracetrack (two parallel sides with opposite curved ends) and rectangular(with curved corners). Still other shapes are possible.

Another characteristic of the preferred separator elements 10 shown, isthat they have media packs which define inner configurations, incross-section (taken orthogonal to a central longitudinal axis) that arenot circular, but rather are defined with a media pack inner surfacehaving one long and one short cross-sectional central axis. One usablecross-sectional shape for the media pack inside surface, is generallyobround or oval cross-section, a specific example of which is anelliptical cross-section matching the outer cross-section. Examples ofother possible shapes include racetrack (two parallel sides withopposite or curved ends) and rectangular (with curved corners). Stillother shapes are possible.

Attention is first directed to FIG. 6. FIG. 6 is a top plan view ofseparator element 130, which could be used as the elements 10, in theassembly of FIG. 1. Separator element 130 has an outer end cap 131. Theend cap 131 is a closed end cap, and would generally be positionedanalogously to end cap 50, FIG. 1, during use.

Referring to FIG. 6, it can be seen that, in cross-section, the element130 has a center 135, with a long cross-sectional axis 136 passingtherethrough, and a short cross-sectional axis 137 also passingtherethrough. The long axis 136 and the short axis 137 are generallyperpendicular to one another. The particular shape of the outerperiphery 139 of element 130 (and its media pack) is ellipsoid,although, again, variations from an ellipse are possible. Beingellipsoid, the element 130 has two opposite, narrowly curved ends 140,separated by two curved sides 141.

Referring to FIGS. 7 and 8, it can be seen that the media pack 142 ofthe element 130 has a fairly constant cross-section, thus an insidecross-sectional surface 139 a of element 130 (or media pack 142) has along axis corresponding long axis 136 (FIG. 6) and a short axiscorresponding to short axis 137 (FIG. 6), which are generallyperpendicular to one another. The particular shape of the innercross-section of the element (and its media pack) is ellipsoid,although, again, variations from an ellipse are possible. Beingellipsoid, the inside surface 139 a has two oppositely narrowly curvedends (inside of ends 140, FIG. 6) separated by two curved sides (insideof sides 141, FIG. 6), FIGS. 7 and 8.

Herein, the term “aspect ratio” will be used to refer to the ratio ofthe length of the long cross-sectional axis 136 to the shortcross-sectional axis 137. In typical constructions, this aspect ratiowill at least 1.3, usually at least 1.5, and typically within the rangeof 1.5 to 2.3, inclusive, for the outer periphery of the end caps andthe media pack.

Still referring to FIG. 6, long axis 136 can be viewed as defining aplane 136 a extending longitudinally through the separator element 130;and axis 137 can be viewed as defining a plane 137 a, extendinglongitudinally through the element 130 orthogonal to the first plane 136a.

Attention is again directed to FIG. 7, which is a cross-sectional viewof separator element 130 taken generally along line 7-7, FIG. 6,(alternately stated, taken along the long axis 136; i.e., in plane 136a). Referring to FIG. 7, separator element 130 includes closed end cap131 having outer perimeter or periphery 139; media pack 142, whichserves the function of media pack 20, FIG. 1; and, open end cap 143,having central aperture 144 therein.

Still referring to FIG. 7, the particular end cap 143 shown includesprojection or spigot 148 projecting axially outwardly therefrom, i.e.,away from media pack 140. The term “axially” in this context is meant torefer to extension in a direction of extension of central longitudinalaxis 149. Spigot 148 includes an outer surface with o-ring 150 thereon,for forming a seal when installed.

The aperture 144 may have any of a variety of cross-sections. It may forexample be circular since its basic function is to permit the gas flowinto interior 142 a of media pack 142, during use. The particularaperture 144 depicted, has a preferred cross-sectional shape with a longcross-section axis and a short cross-section axis, analogously to anoutside perimeter shape 139 of end cap 131 (or to an outside perimetershape of media pack 142). Preferably the aspect ratio of the aperture144 is at least 1.3, usually at least 1.5.

The outside surface 148 a of the spigot 148, may be of any of variety ofshapes. Again a shape having a circular cross-section is usable. Howevertypically and preferably, the outside surface 148 a is configured todefine a perimeter having a long cross-sectional axis and a shortcross-sectional axis, within aspect ratio of at least 1.3, usually atleast 1.5 and typically within the range of 1.5-2.3 inclusive.

Specific construction of the media pack 142, is not critical to thegeneral principles of assembly and configuration described herein, as amatter of choice. In general, the size and construction of the mediapack 140 will be selected based upon such issues as the air flow, thelevel of efficiency of separation desired, the amount of restrictionacceptable, the lifetime of use preferred and the size of spaceavailable.

Components of media packs for air/oil separators are described, forexample, in U.S. Pat. No. 6,093,231; U.S. Pat. No. 6,136,016; WO99/47211; WO 99/43412; UK 1, 603, 519; U.S. Pat. No. 6,419,721; and U.S.Pat. No. 4,836,931, the complete disclosures of the seven identifiedreferences being incorporated herein by reference. The principles ofthese types of arrangements can, for example, be applied for separatorunits herein.

The particular media pack 142 depicted, include a coalescing stage 152and a drain stage 153. The coalescing stage comprises appropriatematerial to cause coalescing of entrained liquid particles within an airstream passing into the coalescing stage. The drain stage operates tocollect coalesced particles, to allow drainage into a sump around theelement.

It is anticipated that the coalescing stage 152 may comprise a formedmedia 8. It is anticipated that the drain stage 153, at least in someinstances, comprises a wrapped felt (for example formed from a felt suchas a polyester felt having a weight of 10 oz/sq.yd.; a permeability of450 cfm/ft² at 0.5 inch H₂O, and a nominal thickness of 0.1-0.2 inches)or air laid material, wrapped around the outside of the coalescing stage152. (A felt could be ultrasonically welded and then inverted and slidover a central liner.)

The thickness of the coalescing stage 158 and drain stage 153 may bevaried, depending on the particular system. A typical example would be:a coalescing medium having a thickness of about 0.4-0.6 inches, forexample 0.5 inches; and a drain stage medium having an overall thicknessof about 0.2-0.3 inches, for example 0.25 inches. For the drain stage,this could be accomplished by using two wraps of a felt ascharacterized.

For the particular media pack 142 depicted, a central liner 154 iscontained centrally within the media pack 140. The liner would typicallybe a porous metal screen, such as an expanded screen or other porousstructure, on which the coalescing stage 152 and drain stage 153 aresupported.

Herein above, it was stated that the coalescing stage 152 may compriseformed media. In general formed media comprises media constructed bydeposition of media fibers onto a former mandrel, from suspension.Adhesives may be applied and/or binder fibers may be used, to helpretain the formed shape on the mandrel. An example for formation ofcoalescing stage 152, would be deposition of fibers from suspension,onto an elliptical inside surface of liner 154.

The media pack 142 may optionally include an inner liner, and/or anouter liner, not specifically shown.

The end caps 131, 143, may be molded or formed from metal. Typicallymolded end caps will be preferred, because the features shown can bereadily molded. The end caps can be molded directly onto the media pack,or be premolded and secured with a potting material.

Attention is now directed to FIG. 8, which shows a cross-section ofseparator element 130, taken along line 8-8, FIG. 6; i.e., taken alongthe short axis 137 or in plane 137 a.

Separator element 130 is configured for in-to-out flow during passage ofgases through media pack 142, in normal operation. As a result, thecoalescing stage 152 is surrounded by the drain stage 153. If theelement were to be utilized in an out-to-in flow application, thecoalescing stage 152 would be positioned around the drain stage 153.That is, in general media pack 142 is configured so that the first stageencountered by gas flow therethrough, is the coalescing stage.

The size of the elements, is a matter of choice for the systemsinvolved. For the example given, a long cross-sectional dimension ofabout 7 inches (for example 6-8 inches), and a short cross-sectionaldimension of about 4 inches (for example about 3-5 inches), will beusable, as well as sizes outside of these ranges. The overall lengthwill vary, depending on the total flow needed through the element, fortypical operation. The example lengths would be about 13 inches up toabout 25 inches, depending on the system. Indeed alternate lengths canbe used. As an example, an element length of about 15 inches should besufficient, with a through put expected of about 350 standard cu./ft.per minute, per element; and a length of about 20 inches should beappropriate, with a through put expected on the order of about 450standard cu./ft. per minute per element; for an element with a 7 inchlong axis and a 4 inch short axis.

VI. A Separator Assembly which Utilizes only One Serviceable SeparatorElement

Attention is now directed to FIGS. 9 and 10. In FIGS. 9 and 10, aseparator assembly 155 is shown, using a single separator element.Assembly 155 may include componentry generally analogous that describefor the arrangement 1, FIGS. 1 and 2. In particular, separator assembly155 includes: housing 156, with cylindrical side wall 156 a and bottom156 b. A drain 157 is provided in the bottom 156 b. Inlet 158 isviewable, as well as tube sheet structure 159, and a preseparatorarrangement 160, comprising skirt 161.

The arrangement includes top 162 and serviceable separator element 163.The serviceable separator element 163 may be in accord with element 130,FIGS. 6-8.

Not viewable in FIG. 9 is the radial outlet 164, FIG. 10.

Other features generally characterized in connection with FIGS. 1-3 canbe used for the arrangement of FIGS. 9 and 10, modified to accommodatethe presence of a single separator element 163.

V. Advantageous Use of Separator Elements Having Non-Circular OuterPeripheries with a Long Cross-Sectional Axis and a Short Cross-SectionalAxis

Non-circular outer peripheries separator elements, in accord with thedisclosure herein, can be utilized to advantage. Typically such usefulseparators are ones that have aspect ratios, as characterized above.Preferred use of these, will be understood by reference to thedepictions of FIGS. 5, 10 and 11.

Referring to FIG. 10, a depiction is presented, showing a gas/liquidseparator assembly 155 having a circular outer wall 156, with a topremoved.

In general, it is preferred to provide a distance X, between an outersurface of a gas/liquid separator 163 and an outlet 164, to provide goodflow without undesirable turbulence or undesirable levels of liquidreaching the outlet, for a typical system, FIG. 10, using a singleelement, a distance X on the order of about 0.9 to 3 inches would bytypical.

If the separator 163 were simply round in cross-section, and such aspace X was maintained, the surface area of the separator would be less,than with the obround shape shown having an aspect ratio as shown. It isnoted that a preferred orientation for the separator element 163, iswith short axis 170 directed toward the outlet 164, and the long axis171 extending generally perpendicular to a center line of the outlet164. (Alternately stated, the element 168 is preferably positioned witha longitudinal cross-sectional plane 171 a in which the long axis 171resides, positioned orthogonal to a center line of the outlet 164.

In order to achieve the preferred orientation shown in FIG. 10, betweenthe rotational orientation of the separator element 163, and the gasoutlet 164, the assembly 155 can be provided with orientation features.For example, a separator 163 can be provided with a elliptical spigot148, FIGS. 7-8, which can only engage an analogously-shaped portion ofthe tube sheet during sealing, when the separator element 163 is inappropriate rotational orientation, around a central longitudinal axis149, FIGS. 7 and 8, relative to outlet 164, FIG. 10. For the particulararrangement shown in FIG. 10, there would only be two such feasiblerotational orientations, and they would be the same due to an overallsymmetry of the shape of element 163 (as mirror images) on each side ofplane 171 a. (In FIG. 10, bolt holes are shown at 173.)

In addition, region 180 of the housing 196, FIG. 9, can be provided withan inner aperture shape through which the element 163 can only pass ifit is oriented appropriately, with respect to the long and shortcross-section axis. It could be done, for example, by providing section180 with an aperture therein defining a similar elliptical shape withthe same aspect ratio, assuming the separator 163 used is one having anelliptical shape.

The unique configurations of separator elements disclosed herein, arealso advantageous in applications in which the assembly includes morethan one separator element therein. An example of this is shown in FIG.5. For the particular arrangement shown, the elements 11 are positionedwith long axes 190 or planes 190 a parallel to one another. The elements11 are spaced from one another (although they could touch) on oppositesides of a center line 193, which extends through outlet 13. Theelements 11 are preferably positioned with the long cross-sectional axes190 or planes 190 a generally parallel to center line 193. Further, theelements 11 are preferably positioned with a short cross-sectional axes194 or planes 194 a parallel to, and preferably co-planar, with oneanother, passing through center axis 47, of the circular sidewall 5 ofhousing 4.

This orientation positions two elements 11 with relatively large mediapack surface areas, within a single, circular outer wall 5, whilemaintaining a substantial spacing Y between each element 185 and outlet182. Again, Y would be chosen to ensure good flow and avoidance of anundesirable amount of liquid reaching the outlet. For a typical twoelement system of the type shown, a distance Y on the order of at leastabout 1.2 inches should be sufficient.

The top piece 200 of sidewall 5, FIG. 3 is shown with an aperture shapeat 62 facilitating proper alignment of the elements 11 uponinstallation.

As with the arrangement of FIGS. 9 and 10, the elements 11 could beconstructed with a spigot analogous to spigot 148, FIGS. 7 and 8, whichcan only properly engage for sealing, with the element 11 appropriatelyradially positioned.

An arrangement in which three serviceable separator elements arepositioned, is shown in FIG. 11. Referring to FIG. 11, at 210 gas/liquidseparator assembly is shown schematically. The gas/liquid separatorassembly 210 has a housing 211 with a circular outer wall 211 a. A gasoutlet 213 is shown, as a radially directed outlet. At 215, central axisfor circular housing 211 is shown, analogous to axis 47, FIG. 1.

Three identically sized and shaped elements 217 are shown positionedwithin interior 218. Each element 217 has a long cross-sectional axis220 or plane 220 a and a short cross-sectional axis 221 or plane 221 a,preferably with an aspect ratio of as described above. The elements 217are positioned with a short axis 221 directed toward central axis 215,and a spacing Z. For a three element system, Z should be selected toavoid undesirable levels of liquid from reaching the outlet, whileproviding good flow characteristics. For a typical three element systemof the type shown, a distance Z on the order of at least about 1.5inches should be sufficient.

The elements 217 are also positioned such that the long axes 220 of afirst two (217 a, 217 b) of the elements are directed toward the outlet213 and such that a third one of the elements (217 c) is positioned withits long axis 220 (and plane 220 a) generally perpendicular to a centralline 224 of the outlet 213. This is accomplished by having the element217 c with its long axis 220 perpendicular to line 224, be the furthestone of the elements 217 c spaced from the outlet 213. It can be seenfrom a review of FIG. 11, that the shape of the elements 217 allows forpositioning of three elements within a circular space, with a relativelylarge total amount of outer peripheral media pack surface of theelements 217 available (by comparison to circular elements).

VI. Depictions of an Example Air/Oil Separator Element, FIGS. 12-15

In FIGS. 12-15, an air/oil separator element 300 is depicted, which canbe used as a separator element in assemblies as previously discussed.Referring to FIG. 12, separator element 300 comprises a media pack 301positioned in extension between a first, open, end cap 305 and a second,closed, end cap 306. The media pack may be as generally describedhereinabove, typically possessing both a coalescing stage and a drainstage. Various liners and separators can be included within the mediapack 301, in general accord with the principles discussed above.

The open end cap 305 is positioned on a first end 301 a of the mediapack 301. The end cap 305 includes spigot 310 having an open aperture311. The spigot 310 has an elliptical shape. The spigot 310 includesgroove 312, for positioning therein of an o-ring.

Still referring to FIG. 12, end cap 306 is a closed end cap, and issecured to end 301 b of the media pack 301.

In FIG. 13, a top plan view of the elliptical air/oil separator element300 is depicted, i.e., in FIG. 13 the element 300 is viewed toward endcap 305.

In FIG. 14, elliptical air/oil separator element 300 is depicted incross-sectional view, taken along line 14-14, FIG. 12. In FIG. 14, itcan be seen that the end cap 310 is formed from two parts: piece 310 a,which is secured to an end of the media pack 301; and, piece 310 b,which is secured inside of stem 310 c of piece 310 a.

More specifically, piece 310 includes shoulder 310 b and axialprojecting stem 310 c. The stem 310 c has an elliptical shape. Piece 310b includes upper outwardly directing projection 310 e and shoulder 310f, along with inner projection 310 g. Piece 310 b is inserted into anaperture defined by stem 310 a, until shoulder 310 f engages shelf 310 hof piece 310 c. Shoulder 310 f of piece 310 b is positioned such thatwhen it is stopped, by engagement with shelf 310 h, o-ring gap 312 ispositioned formed between projection 310 e and stem 310 c. In thismanner, if desired, an o-ring can be formed in a two-piece end cap,without the need for a machining operation to form the groove. Thepieces 310 a, 310 b can each be metal pieces, or molded plastic pieces,as desired.

Of course end cap 310 could be a single molded piece or single machinedpiece, if desired.

When end cap 310 is formed in two pieces as shown, the two pieces 310 a,310 b can be secured to one another in a variety of means including bywelding or with adhesive or by other similar effective approaches.

End cap 305 includes rim 305 a, which surrounds end 301 a of media pack301.

Referring to FIG. 14, end cap 306 includes outer side wall 306 a, endwall 306 b and inner ring projection 306 c. End cap 306 can be formedfrom a single piece, for example a metal piece or a molded plasticpiece, or it could be formed in two or more pieces, as desired.

It is noted that rim 306 a and rim 305 a for end cap 310; each ispositioned spaced radially outwardly from the media pack 301. This isnot required. However using a size such as this for certain end capsallows various sized media packs to be set into the same pair of endcaps, where the size varies somewhat in media pack thickness. This canbe advantageous for some applications.

Still referring to FIG. 14, it is noted that the particular media pack301 depicted comprises outer drain stage media 320, an inner media liner321 and inner coalescing stage 322. Of course additional structure suchas an inner liner or an outer liner could be used.

In FIG. 15, another cross-sectional view of element 300 is depicted, inthis instance taken along the shorter axis.

For typical preferred elements in accord with the construction of FIGS.12-15, preferred aspect ratios of the longer dimension to the shorterdimension for the various parts would be as follows:

-   -   1. For the outer perimeter of closed end cap 306, preferably the        aspect ratio for the longer elliptical axis to the shorter        elliptical axis would be at least 1.3, usually at least 1.5 and        typically within the range of 1.5-2.3 inclusive. An example        would be 1.65-1.85.    -   2. The outer peripheral rim 305 a of the open end cap 305, would        have similar preferred aspect ratios as stated in the previous        paragraph for the closed end cap 306.    -   3. The ellipse formed by projection 310 e, on end cap 310,        preferably has an aspect ratio (longer elliptical axis to        shorter elliptical axis) of at least 1.3, usually at least 1.5        and typically within the range of 1.5-2.5. An example would be        about 2.1-2.4. This range of ratios would, of course, also        correspond to the seal dimensions.    -   4. For the element configured in FIGS. 12-15, the elliptical        aperture 311 would preferably have the following aspect ratios,        for longer elliptical axis to shorter elliptical axis: at least        1.3, usually at least 1.5 and typically within the range of        1.5-3.0. An example would be 2.4-2.7.    -   5. The inside surface 322 a of the coalescing stage media 322,        would typically have an aspect ratio (longer elliptical axis to        shorter elliptical axis) of at least 1.3, typically at least 1.5        and usually within the range of 1.8-2.6, inclusive. An example        would be about 2.2-2.6.    -   6. The outside surface of 321 a of the drain stage 321 would        typically have an aspect ratio (longer elliptical axis to        shorter elliptical axis) of at least 1.3, typically at least        1.5, and usually within the range of 1.5-2.3, inclusive. An        example would be 1.65-2.1.

In FIGS. 14 and 15, some letter designations are provided, to allowidentification of example dimensions. Although a variety of differentsized units can be made, these dimensions will help indicate generalconstruction that is useable for example systems of the type described,or which can be adapted by modification in size for application to avariety of still more systems. The indicated dimensions are as follows:

-   -   A=139.4 mm (5.49 inch);    -   B=125.2 mm (4.93 inch);    -   C=131.1 mm (5.16 inch);    -   D=156.5 mm (6.16 inch);    -   E=158.0 mm (6.22 inch) (dimension to outside of liner);    -   F=167.6 mm (6.60 inch);    -   G=177.8 mm (7.0 inch)    -   H=249.9 mm (9.84 inch);    -   I=254.0 mm (10 inch);    -   J=276.2 mm (10.88 inch);    -   K=63.2 mm (2.49 inch);    -   L=49.0 mm (1.93 inch);    -   M=54.9 mm (2.16 inch);    -   N=80.3 mm (3.16 inch);    -   O=81.8 mm (3.22 inch) (dimension to outside of liner);    -   P=91.4 mm (3.60 inch); and    -   Q=101.6 mm (4.0 inch).

Of course a variety of alternate air/oil separator elements, ofdifferent dimensions, can be used employing principles according to thepresent disclosure.

1. A gas/liquid separator element comprising: (a) first and second,opposite, end caps; (b) a media pack extending between the first andsecond end caps and defining an open central interior; (i) the mediapack including a drain stage and a coalescing stage; (ii) the media packhaving a cross-sectional periphery with a perimeter shape having a longcross-sectional axis, a short cross-sectional axis and an aspect ratioof at least 1.3; and (c) an outwardly directed spigot having anon-circular cross-section shape.
 2. A gas/liquid separator elementaccording to claim 1 wherein: (a) the media pack cross-sectionalperiphery is elliptical with an aspect ratio within the range of 1.5 to2.3, inclusive.
 3. A gas/liquid separator element according to claim 1wherein: (a) the coalescing stage is surrounded by the drain stage, andthe element is configured for in-to-out flow in normal use.
 4. Agas/liquid separator element according to claim 3 wherein: (a) the firstend cap is a closed end cap.
 5. A gas/liquid separator element accordingto claim 4 wherein: (a) the second end cap has a non-circular aperturehaving a first, long, axis and a second, short, axis with an aspectratio of at least 1.3.
 6. A gas/liquid separator element according toclaim 5 wherein: (a) the spigot has a cross-sectional outer peripherywith an aspect ratio of at least 1.3.
 7. A gas/liquid separator elementaccording to claim 6 wherein: (a) the spigot has a cross-sectional outerperiphery shape with an aspect ratio of at least 1.5.
 8. A gas/liquidseparator element according to claim 7 including: (a) an o-ringpositioned on an exterior of the spigot.
 9. A gas/liquid separatorelement according to claim 8 wherein: (a) the coalescing stage comprisesa formed media positioned against an interior surface of an ellipticalporous tube.
 10. A gas/liquid separator element comprising: (a) firstand second, opposite, end caps; and (b) a media pack extending betweenthe first and second end caps and defining an open central interior, (i)the media pack including a drain stage surrounding a coalescing stage;(ii) the media pack having a cross-sectional periphery with a perimetershape having a long cross-sectional axis, a short cross-sectional axisand an aspect ratio of at least 1.3.
 11. A gas/liquid separator elementaccording to claim 10 including: (a) a porous liner positioned betweenthe drain stage and the coalescing stage.
 12. A gas/liquid separatorelement comprising: (a) first and second, opposite, end caps; (b) amedia pack extending between the first and second end caps and definingan open central interior; (i) the media pack having a drain stage and acoalescing stage; (ii) the media pack interior having a cross-sectionshape with a long cross-sectional axis, a short cross-sectional axis andan aspect ratio of at least 1.3.
 13. A gas/liquid separator elementaccording to claim 12 wherein: (a) the media pack has a cross-sectionalperiphery with an outer perimeter shape having a long cross-sectionalaxis, a short cross-sectional axis and an aspect ratio of at least 1.5.14. A gas/liquid separator element according to claim 13 wherein: (a)the aspect ratio of the media pack interior is at least 1.3.
 15. Agas/liquid separator assembly comprising: (a) a vessel including: anouter wall; a gas flow inlet projecting through the outer wall, a gasflow outlet projecting through the outer wall; and, a lower sump; (b) atube sheet arrangement separating the vessel into an upper region and alower region; (i) the tube sheet arrangement being positioned so thatthe gas flow inlet is in direct communication with the lower region andthe gas flow outlet is positioned to receive gas flow directly from theupper region; and, (c) at least one removable and replaceable separatorelement operably secured to the tube sheet in a position with a mediapack projecting into the upper region; each separator elementcomprising: (i) first and second, opposite, end caps; (ii) a media packextending between the first and second end caps and defining an opencentral interior; (A) the media pack including a drain stage and acoalescing stage; (B) the media pack having a cross-sectional peripherywith a perimeter shape having a long cross-sectional axis, a shortcross-sectional axis and an aspect ratio of at least 1.3; and (iii) anoutwardly directed spigot having a non-circular cross-section shape. 16.A gas/liquid separator assembly according to claim 15 wherein: (a) thegas flow outlet is a radial outlet with a radially directed outlet axis;and, (b) the assembly includes only one separator element; and, (c) theseparator element is positioned with a long cross-sectional axis thereofgenerally orthogonal to the outlet axis.
 17. A gas/liquid separatorassembly according to claim 15 wherein: (a) the gas flow outlet is aradial outlet with a radially directed outlet axis; (b) the assemblyincludes only two separator elements; and, (c) the two separatorelements are positioned with: (i) the outlet central axis directedbetween the two separator elements; and (ii) the longer cross-sectionalaxis of each element aligned generally parallel with the outlet centralaxis.
 18. A gas/liquid separator according to claim 15 wherein: (a) thegas flow outlet is a radial outlet with a radially directed outlet axis;(b) the assembly includes only three separator elements; (c) a first twoof the three separator elements are each positioned with: (i) the outletcentral axis directed between them; and (ii) with a longercross-sectional axis of each of the first two of the three separatorelements directed toward the gas flow outlet; and, (d) a third one ofthe three separator elements is positioned with: (i) the outlet centralaxis intersecting the third separator element; and (ii) a longercross-sectional axis of the third separator element generally orthogonalto the outlet central axis; (e) the third separator element beingpositioned further from the outlet than the first two of the separatorelements.
 19. A gas/liquid separator assembly according to claim 15including: (a) a preseparation assembly including: (i) a radiallycontinuous tube sheet structure portion positioned spaced from thevessel outer wall to define a gas flow annulus therebetween, (ii) aninlet skirt extending between the tube sheet structure and the vesselouter wall; (A) the gas flow inlet being positioned to direct inlet gasflow into the gas flow annulus above the inlet skirt; (B) the inletskirt including at least one downcomer channel at a location radiallyspaced from the inlet; and, (iii) a radial vane positioned between thedowncomer channel and the gas flow inlet to direct gases through aradial path of at least 70° before the gases can pass from the gas flowinlet through the downcomer channel; and, (b) the at least one removableand replaceable separator element being surrounded by, and spaced from,the gas flow inlet by the tube sheet structure portion.
 20. A gas/liquidseparator assembly according to claim 19 wherein: (a) the radial vane ispositioned to direct gases through a radial path of at least 180° beforethe gases can pass from the gas flow inlet through the downcomerchannel.
 21. A method of separating gas and liquid from a gas/liquidmixture including a step of: (a) passing the gas/liquid mixture througha separator element having a media pack including a coalescing stage anda drain stage, and having a cross-sectional aspect ratio of at least1.3; (i) said method including passing the gas/liquid mixture with anin-to-out flow.
 22. A method of assembling a gas/liquid separatorassembly according to claim 15 for operation, including a step of: (a)positioning the at least one separator element within the housing, asdescribed.